Method of cleaning grain.



NZM-MER. METHGD OFGLEANING GRAIN.

A APlfLIoATIoN FILED Arma, 1909, Patented ont; 18 1910.

NATHAN ZIMMER, OF HOPKINSVILLE, KENTUCKY.

METHOD 0F CLEANING GRAIN.

Specification of Letters Patent.

Patented Oct. 18, 1910.

Application led April 8, 1909. Serial No. 488,658.

To aZZ whom it may concern.'

Be it known that I, NATHAN ZIMMER, a citizen of the United States,residing at Hopkinsville,.in the county of Christian and State ofKentucky, have invented a new and useful Method of Cleaning Grain, ofwhich the following is a specication.

This invention has reference to improvements in cleaning grain, and moreparticularly relates to a method of cleaning wheat preparatory togrinding the same into flour.

A wheat grain separated from the husk is found to have a surfaceconsisting of several layers of cells which together form the hull orbran. The outer layer of the hull or bran, which layer is known as thebeewing is usually contaminated by dirt and other deleterious matter,and often contains germs and insect eggs, which are harmful to the wheatand to the flour made therefrom. In the ordinary process of cleaningwheat preparatory togrinding the same it is customary to wet the wheatso that during the grinding operation this bee-wing will yadhere to thehull or bran separated from the body of the grain during the grindingprocess, the bee-wing then adhering to the bran because of its moistcondition and is carried away with the bran during the bolting process.However, quantities of this bee-wing are ground up very fine and passthrough the bolting clot-h with the flour and so serve to darken theflour as well as carrying into the flour germs and other deleteriousmatter which nds lodgment in the outer coating of the hull of the grain.

It is the object of the present invention to cause the separation ofthis outer coating or bee-wing from the grain in such manner that onpassing the treated grain through a scouring machine the superficiallayer of cells is separated from the wheat grain without disturbing theother layers constituting the bran. Thus the grain when delivered to themill for grinding is thoroughly cleansed from all harmful' matter andalso matter liable to darken the flour produced from the grain bypassing through the bolting cloth during the operation of bolting.

In carrying out the process or method forming the subject matter of thepresent invention various apparatus may be employed and so in theaccompanying drawing forming a part of this specification a more or lessschematic structure is shown and to this drawing reference is had in thefollowing description.

Before being' treated to the method of the present invention the grainis passed through a milling separator and a scouring machine in theusual manner. The grain is then deposited in a conveyer into which issprayed or otherwise caused to flow a suitable quantity of water tomoisten the grain. The quantity of water cannot be given with strictdeniteness since it will vary in accordance to the condition and kind ofwheat, but about one pound of water to the bushel of wheat willconstitute an average quantity. The moistened wheat is carried along bythe conveyer and is discharged from the latter into a suitable tank orreceptacle in which the moistened grain is permitted to stay for a timesay from ten to thirty minutes thus allowing the moisture to penetratethe superficial covering of the bran or hull of the grain.

In the drawing' the initial reservoir for the grain into which it isreceived after having passed through the milling separator and thescouring machine after the usual practice, is indicated at l, theconveyer into one end of which the grain flows from the reservoir l isindicated at 2, and the means for introducing water into the conveyer isshown as a pipe 3 including a regulating valve 4t and coming from astorage tank 5 which latter may be taken as indicative of any source ofwater supply. The conveyer may be of the ordinary type and consequentlyits interior construction is not shown in the drawings. The conveyershaft may have power applied thereto through a pulley 6.

The tank or receptacle into which the moistened grain falls from theconveyer is indicated at 7 and this tank is shown as an upright tankwith a hopper bottom 8 provided with a conical deflector 9 just abovethe hopper bottom 8 so that grain passing through the receptacle 7 tothe funnel end l() of the hopper bottom 8 will be diverted toward thesides of the hopper 8 and therefore the tendency of the grain to travelin a central stream through the tank 7 with a surrounding quiescent bodyof grain is prevented. The fiow of grain from the bottom of the hopper 8is regulated by a suitable slide valve 1l.

The holding of the grain in the tank or receptacle 7 for a time allowsthe moisture to penetrate the superficial covering of the l bran andthen the grain is permitted to pass into another tank 12 where it issubjected to the action of steam under pressure, the steam inlet andoutlet pipes being indicated at 13 and 14 and these pipes includesuitable valves 15 which may be of the type maintaining a constantpressure of steam in the tank irrespective of fluctuations of steam atthe source of supply. A thermometer 16 may also be provided so that anobserver may at all times ascertain the temperature within the tank.From the tank 12 the grain passes by a conduit 17 including a suitableregulating gage 1S, to scouring machines 19 and 20 in series and then toa suitable bin 21. The steam acting on the grain within the tank 12should be under considerable pressure and I have found in actualpractice that about forty pounds steam pressure giving a temperature ofabout 297 Fahrenheit7 gives most excellent results, but I have obtainedgood results at other pressures and therefore thel invention is notlimited to the pressure mentioned.

The theory of operation of the method is that the preliminary moisteningof the grain at the conveyer and the holding` of the grain in the tankor receptacle after leaving the conveyer chills and contracts thesuperficial layer and then the sudden heating of the grain by the steamexpands the grain and causes the superficial layer or bee-wing toblister or peel away and break ofi. New when the grain passes to thescouring machine this bee-wing is readily removed without affecting theunder layers constituting the hull or bran. It is to be understoodhowever that I am by no means confined to the theory advanced, butactual practice of the invention has shown that the supercial coating orbee-wing is most effectually separated from the body of the grain whenthe grain is first moistened and subsequently subjected to steam underpressure. The resultant grain is entirely cleared of the beewing and maythen be ground and bolted all germs and weevil eggs so moving' theloosened vlayer in the usual manner giving a very white flour free fromall matter it. Furthermore the treatment to the hot steam thoroughlysterilizes the grain killing that the wheat may be stored in bulkwithout harm.

In subjecting the grain to the action of steam the grain is permitted toflow in a stream through the steam and is thereby acted upon by thesteam over the entire surface of each grain.

that is claimed is 1. rllhe method of treating grain to remove thesuperficial or bee-wing layer preparatory to grinding the grain, whichconsists in first moistening the grain, then causing a blistering, orloosening of the bee-wing layer without disturbing the underlying branlayers by flowing the moistened grain in a stream through an atmosphereof steam, and then removing the loosened bee-wing layer from the grain.

2. The method of treating grain to remove the superficial or bee-winglayer preparatory to grinding the grain7 which consists in moisteningthe grain with cold water, then causing the moistened grain to gravitatein a stream through an atm0sphere of steam under pressure to loosen orblister the bee-wing layer without disturbing the underlying branlayers, and then reor blistered bee-wing from the grain.

3. The method of treating wheat to remove the superficial or bee-wingcoating which consists in rst moistening the wheat with cold water, andthen flowing the wheat so moistened through an atmosphere of steam underpressure.

In testimony that I claim the foregoing as my own, I have hereto affixedmy signature in the presence of two witnesses.

NATHAN ZIMMER.

Witnesses:

E. HUME TALBERT, F. T. CHAPMAN.

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